Research Profile - The best intentions
A pregnant woman may think she's protecting her baby by foregoing her daily asthma treatments, but the best evidence suggests she should carry on with the drugs to help her child be healthy.
A pregnant women who stops taking her asthma medication to spare her baby from exposure to corticosteroids may be doing more harm than good.
"The mother may decide to stop because she feels that she's not doing too badly, she's not too short of breath, and she is afraid that the medication may be bad for the fetus," says researcher Dr. Lucie Blais of the Université de Montréal. "My hypothesis is that the baby will suffer from the asthma before the mother, or maybe more than the mother."
All people with asthma – not just pregnant women – tend to take their medication sporadically, discontinuing treatment when the breath-stealing condition is under control or causing minimum problems. According to Dr. Blais, however, asthma is a chronic condition with episodic flare-ups and requires everyday treatment.
At a Glance
Who – Dr. Lucie Blais, Associate Professor, Faculty of Pharmacy, Université de Montréal, Researcher, Research Center, Hôpital du Sacré-Coeur de Montréal
Issue – Many women with asthma stop using their inhaled corticosteroid medications during pregnancy, which raises the risk of adverse maternal and infant outcomes.
Approach – Dr. Blais is leading a study of more than 8,000 asthmatic women to investigate the impact of discontinuation or reduction of corticosteroid used during pregnancy.
Impact – Findings from the research will provide evidence to better protect the health of the pregnant woman and her child and reduce costs for the health care system.
"Very often, what we see is treatment of just the asthmatic exacerbation. Between exacerbations, however, there may be very little treatment."
Dr. Blais says the tendency to forego treatment "might be amplified during pregnancy, because if a woman is taking a medication knowing there is corticosteroids in it, even if it's inhaled, she might be afraid that it may do some harm to the fetus."
Best intentions notwithstanding, it's important for pregnant women to stick with their medication regimen because an asthma attack can cause the blood's oxygen level to dip for both the mother and the baby she is carrying. "From the evidence that we have, the best recommendation is to continue inhaled corticosteroids to keep the asthma under control," says Dr. Blais.
Funded by the Canadian Institutes of Health Research, Dr. Blais is examining the health effects of non-adherence to asthma therapies during pregnancy. Her studies so far indicate that while women who suffer severe asthma continue taking their corticosteroids during their pregnancy, those with mild to moderate asthma tend to put the puffers away until after the baby is born.
When she began her study, Dr. Blais expected to find that women who stopped taking their corticosteroids during pregnancy showed greater "adverse perinatal outcomes" in terms of lower birth weights or increased premature births. However, she bumped up against a "confounding bias" in the results because the women who quit their meds had less severe asthma compared to severely asthmatic women who stayed with the therapy to cope with their condition. It became an apples to oranges comparison.
"Because of that, it's very difficult to see if inhaled corticosteroids add truly beneficial effects," says Dr. Blais. "So, we focused more on asthma severity. We found that women with moderate to severe asthma, compared to mild asthma, are more likely to have babies that are small for gestational age – which is a marker for intrauterine growth."
As part of the study, Dr. Blais' research team examined a decade of health records for a cohort of more than 8,000 children – from birth to 10 years of age – who were born to asthmatic mothers. A subset of the mothers were mailed questionnaires to gather additional information about the family's medical history, lifestyle habits and environment. Data gathered and analyzed so far indicates that failing to control asthma during pregnancy has a negative impact on the child.
Dr. Blais strongly recommends that women get their asthma under control with an optimal dose of inhaled corticosteroids before they become pregnant.
"It's important because their physician will be reluctant to add a medication or increase the dose of the currently used medication during pregnancy. So if you know before pregnancy what your dose should be and the treatment has been optimized, then you can continue the same treatment during pregnancy."
By the Numbers
- The prevalence of asthma among pregnant women is between 4% to 7% – one of the most frequent chronic diseases encountered during pregnancy.
- There is no definitive evidence to suggest asthma gets worse or better during pregnancy. Studies so far indicate 33% of pregnant women experience improvements, 33% experience a worsening of their condition and 33% experience no change.
- An analysis of data gathered on a cohort of asthmatic women indicated about 50% stopped or reduced their use of inhaled corticosteroids during pregnancy.
"It's not the disease that is episodic, it's the symptoms. The disease is always there. And if people don't take their medication, they will have more frequent exacerbations."
-- Dr. Lucie Blais